The present invention concerns the use of MP52 or/and MP121, two growth or/and differentiation factors of the TGF-xcex2 superfamily, for the treatment and prevention of diseases of the nervous system or/and for the treatment of neuropathological situations which are caused by ageing of the nervous system. In addition the invention concerns pharmaceutical agents for the treatment or prevention of the above indications which contain MP52 or/and MP121.
Many growth factors from the TGF-xcex2 superfamily (Kingsley, Genes and Development 8, 133-146 (1994) and the literature cited therein) are relevant for a wide range of medical treatment methods and applications which in particular concern wound healing and tissue regeneration. These include in particular members of the TGF-xcex2 (Transforming Growth Factor, see e.g. Roberts and Sporn, Handbook of Experimental Pharmacology 95 (1990), p. 419-472, eds. Sporn and Roberts) the BMP (Bone Morphogenetic Protein, see e.g. Rosen and Thies, Growth Factors in Perinatal Development (1993), p. 39-58, eds. Tsang, Lemons and Balistreri) and the inhibin/activin (see e.g. Vale et al., The Physiology of Reproduction, Second Edition, (1994), p. 1861-1878, eds. Knobil and Neill) family. Although the mature parts of members of this family have high amino acid homologies, in particular usually 7 conserved cysteines, their exact functions vary considerably. The TGF-xcex2-like proteins belong to a structural superfamily which all have a cystine knot motif (Cell, vol. 73 (1993), p. 421-424). Further members of this superfamily are proteins from the NGF (nerve growth factor)-/neurotrophin family and PDGF (platelet derived growth factor) family. Individual growth factors often exhibit several functions simultaneously so that their use is of interest for various medical indications.
Some of these multifunctional proteins also have survival promoting effects on neurones in addition to functions such as e.g. regulation of the proliferation and differentiation in many cell types (Roberts and Sporn, Handbook of Experimental Pharmacology 95 (1990), p. 419-472, eds. Sporn and Roberts; Sakurai et al., J. Biol. Chem. 269 (1994), p. 14118-14122). Thus for example trophic effects on embryonic motor and sensory neurones were demonstrated for TGF-xcex2 in vitro (Martinou et al., Devl. Brain Res. 52, p. 175-181 (1990) and Chalazonitis et al., Dev. Biol. 152, p. 121-132 (1992)). In addition effects promoting survival were shown on dopaminergic neurones of the midbrain for the proteins TGF-xcex2-1, -2, -3, activin A and GDNF (glial cell line-derived neurotrophic factor), a protein which has structural similarities to TGF-xcex2 superfamily members but these effects were not mediated via astrocytes (Krieglstein et al., EMBO J. 14, p. 736-742 (1995)).
WO 93/16099, WO 95/04819 and WO96/01316 disclose the DNA and protein sequences of TGF-xcex2-like proteins in particular of MP52 and MP121. In WO 95/04819 a cartilage and bone-inducing effect is disclosed for MP52.
The occurrence of proteins of the TGF-xcex2 superfamily in various tissue stages and development stages corresponds with differences with regard to their exact functions as well as target sites, life-span, requirements for auxiliary factors, necessary cellular physiological environment and/or resistance to degradation.
The object of the present invention is to provide a protein which enables a treatment or prevention of diseases of the nervous system. Of interest are the treatment of disorders or losses of nervous functions. These may be caused by acute pathological states such as in cerebrovascular, inflammatory, infectious, metabolic-like deficiencies or/and deficiencies caused by toxic influences, injuries, tumour growth or operative procedures. In addition disorders or losses of nervous functions can be caused by chronic pathological states such as above all neurodegenerative diseases. Neuropathological situations are also often caused by the ageing of the nervous system.
This object is achieved by the use of biologically active MP52 or/and MP121 for the treatment or/and prevention of diseases of the nervous system or/and for the treatment of neuropathological situations which are caused by the ageing of the nervous system.
It was possible to show with the present invention that MP52 has a positive influence on the survival of dopaminergic neurones (see FIG. 3). However, in contrast to TFG-xcex2s and activin A this influence is mediated at least partially by astrocytes associated with nerve cells (see FIG. 4). Hence MP52 is useful for the treatment or prevention of diseases of the nervous system in particular diseases which affect the brain. In this connection neurodegenerative diseases are of particular interest such as e.g. Parkinson""s disease and possibly also diseases such as Alzheimer""s or Huntington""s Chorea. In addition the application of MP52 promotes the survival of neurones and thus maintains nervous functions. All potential uses are applicable to acute as well as to chronic pathological states and this is also true of the preventive measures. In this case acute pathological states are primarily understood as cerebrovascular, inflammatory, infectious, metabolic-like deficiency phenomena or/and deficiencies caused by toxic influences, injuries, tumour growth or operative procedures.
A chronic pathological state which can be treated within the scope of the invention is for example a neurodegenerative disease. In addition it could also be shown with the present invention that MP52 also has a stimulating influence on neurones of the retina. During the development of the visual system axons migrate from the ganglion cells of the retina to special regions in the brain. Several groups have been able to show that soluble factors which were isolated from the visual regions of the brain can stimulate the ganglion cells in the retina (Nurcombe, V. and Bennett, M. R., Exp. Brain Res. 44, 249-258 (1981), Hyndman, A. G., Adler, R., Dev. Neurosci. 5, 40-53 (1982), Turner, J. E. et al., Dev. Brain Res. 6, 77-83 (1983), Carri, N. G. and Ebendal, T., Dev. Brain Res. 6, 219-229 (1983)). The formation of nerve fiber fascicles which are probably optical axons stemming from the retinal ganglion cells depends on neurotrophic factors.
Experiments with MP52 showed that this protein can also act as a neurotrophic factor in this system.
Thus using freshly isolated tissue cultures of embryonic retina from chicken it could be shown that MP52 significantly promotes the outgrowth of nerve fibers (see FIG. 6 and table 1 for this).
During these experiments it was also possible to show that further members of the TGF-xcex2 family also have a stimulating effect. These include in particular also MP121 (WO93/16099 and WO96/01316) which has about the same strong effect as MP52 (see FIG. 6 and table 2 for this).
The activities of MP52 and MP121 can be used to heal diseases of the eye and especially the retina and the optic nerve. In this connection the treatment of injuries to the neuronal layer of the retina and the optic nerve should be emphasized. Such injuries could for example be caused by accidents, inflammation or circulatory disturbances. Applications in retinal transplantations are also advantageous. In addition a healing or alleviation of damage to other brain nerves should also be of importance. In this case emphasis is made for example on the trigeminus (nervus trigeminus) which also innervates parts of the eye. Thus members of the TGF-xcex2 family in particular MP52 and MP121 can also be used for corneal transplantations. The growth of the cornea is also influenced by the nerve supply. An application in the case of only segmental damage to the cornea is also conceivable such as those which occur in the case of herpes infections in the eye.
In particular applications for degenerative diseases of the eye surface should be underscored.
In a preferred embodiment of the present invention the following are used as biologically active MP52
(a) the mature part and optionally further functional parts of the protein sequence shown in SEQ ID NO.1
(b) parts of the mature protein which essentially have the same activity;
(c) mature proteins with a modified N-terminus which have essentially the same activity;
(d) a mature protein or parts thereof which has a different amino acid sequence due to its origin from other vertebrates but essentially retains the same activity.
In another preferred embodiment the following are used as biologically active MP121
(a) the mature part and optionally further functional parts of the protein sequence shown in SEQ ID NO.3 or 4
(b) parts of the mature protein which essentially have the same activity;
(c) mature proteins with a modified N-terminus which have essentially the same activity;
(d) a mature protein or parts thereof which has a different amino acid sequence due to its origin from other vertebrates but essentially retains the same activity.